Targeted irrigation using a central pivot irrigation system with a sensor network

ABSTRACT

A system includes a plurality of optical sensors located along at least one pipe segment of a rotating arm that pivots around an irrigation area of a field, the plurality of optical sensors continuously monitors soil and vegetation conditions and transmits sensed data to a central computer, and a plurality of in-ground sensors scattered in the irrigation area of the field, the plurality of in-ground sensors continuously monitors soil conditions and transmits sensed data to a plurality of gateway devices located in the rotating arm, the plurality of gateway devices transmits data from the plurality of in-ground sensors to the central computer where data from the plurality of optical sensors and the plurality of in-ground sensors is integrated with external data to determine water and fertilizer needs based on which an irrigation schedule is created.

BACKGROUND

The present invention generally relates to central pivot irrigationsystems and more particularly to implementing targeted irrigation usingthe central pivot irrigation system with a wireless sensor network. Theseries of practices implemented to accurately and effectively allocatewater to growing crops may be generally referred to as precisionagriculture. Precision agriculture may help reduce operating costs whilesimultaneously improving crop yield. Precision agriculture may includeirrigation systems such as a central pivot irrigation system, which maybe commonly used in current farming practices to allocate water and/orfertilizers to areas of land on which a crop may be growing. Centralpivot irrigation systems are most commonly used in large farms withscattered field sites and multiple crops, especially because of theirease of operation and efficiency.

Central pivot irrigation systems may generally include a central tower,or pivot point, located at the center of the irrigating area and arotating arm pivoting around the central tower at an elevated positionabove the ground. The rotating arm may include a pipe or conduitextending laterally across the rotating arm away from the central tower.Water and/or fertilizers may be sprayed from the pipe at predeterminedpoints along the conduit in which sprinklers or nozzles have beenlocated. The rotating arm may further include trusses or towerssupported by wheels to maintain the pipe in the elevated position abovethe ground. As the rotating arm pivots around the central tower, waterand/or fertilizers may be fed and sprinkled in a circular pattern.

Variability in field characteristics such as, for example, vegetationcover, soil moisture and canopy leaf temperature may affect theeffectiveness of the central pivot irrigation system in determining whenirrigation may be needed since equal amounts of water may be generallydispensed to the entire field. Also, determining the exact geospatiallocation where precision agriculture, including variable irrigation ratemanagement, may need to be applied may pose a challenge to currentfarming practices due to the lack of a continuous monitoring system.

SUMMARY

According to an embodiment of the present disclosure, a system mayinclude: a plurality of optical sensors located along at least one pipesegment of a rotating arm that pivots around an irrigation area of afield, the plurality of optical sensors may continuously monitor soiland vegetation conditions and may transmit sensed data to a centralcomputer, and a plurality of in-ground sensors scattered in theirrigation area of the field, the plurality of in-ground sensors maycontinuously monitor soil conditions and may transmit sensed data to aplurality of gateway devices located in the rotating arm, the pluralityof gateway devices may transmit data from the plurality of in-groundsensors to the central computer where data from the plurality of opticalsensors and the plurality of in-ground sensors may be integrated withexternal data to determine water and fertilizer needs based on which anirrigation schedule is created.

According to another embodiment of the present disclosure, a system mayinclude: a plurality of pipe segments joined together end-to-end andsupported above the ground on wheeled framed towers, the plurality ofpipe segments may be rotatably attached at one end to a central towersuch that they rotate freely about the central tower, each pipe segmentmay include one or more nozzles for dispensing a fluid on an irrigationarea below the pipe segments, a plurality of optical sensors locatedalong one or more of the pipe segments, the optical sensors may estimatesoil and vegetation properties and may generate optical sensor data, aplurality of in-ground sensors at least partially embedded into the soilwithin the irrigation area, the in-ground sensors may detect soilproperties and may generate in-ground sensor data, a gateway deviceattached to one or more of the wheeled framed towers, the plurality ofin-ground sensors may wirelessly transmit the soil properties to thegateway device, and a central computer located in the central tower, thegateway device may wirelessly transmits the in-ground sensor data to thecentral computer to determine the irrigation needs of the irrigationarea in the form of an irrigation map by processing the in-ground sensordata, the optical sensor data, and external data, the central computermay communicate with individual flow control valves corresponding witheach nozzle to open or close to irrigate one or more zones identified bythe irrigation map.

According to another embodiment of the present disclosure, a method mayinclude: providing a central pivot irrigation system including aplurality of pipe segments joined together end-to-end and supportedabove the ground on wheeled framed towers, the plurality of pipesegments may be rotatably attached at one end to a central tower suchthat they rotate freely about the central tower, each pipe segmentincluding one or more nozzles for dispensing a fluid on an irrigationarea below the pipe segments, acquiring in-field data from a wirelesssensor network including: a plurality of optical sensors located alongone or more of the pipe segments, the optical sensors estimating soiland vegetation properties and generating optical sensor data, aplurality of in-ground sensors at least partially embedded into the soilwithin the irrigation area, the in-ground sensors detecting soilproperties and generating in-ground sensor data, and a gateway deviceattached to one or more of the wheeled framed towers, the plurality ofin-ground sensors wirelessly transmitting the soil properties to thegateway device and the gateway device wirelessly transmitting thein-ground sensor data to a central computer located in the centraltower, and determining in the central computer irrigation needs of theirrigation area in the form of an irrigation map by processing thein-ground sensor data, the optical sensor data, and external data, thecentral computer may communicate with individual flow control valvescorresponding with each nozzle to open or close to irrigate one or morezones identified by the irrigation map.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The following detailed description, given by way of example and notintended to limit the invention solely thereto, will best be appreciatedin conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic view of a central pivot irrigation systemdepicting an irrigation area of a field, according to an embodiment ofthe present disclosure;

FIG. 2 is a schematic view of the central pivot irrigation systemincluding a plurality of optical sensors on a rotating arm, according toan embodiment of the present disclosure;

FIG. 3 is a schematic view of the central pivot irrigation systemincluding a plurality of in-ground sensors and a plurality of gatewaydevices on the rotating arm, according to an embodiment of the presentdisclosure;

FIG. 4 is a functional block diagram of a hybrid wired and wirelesscomputing environment, according to an embodiment of the presentdisclosure;

FIG. 5 is a flow chart depicting a sequence of steps for targetedirrigation using the central pivot irrigation system and the wirelesssensor network, according to an embodiment of the present disclosure;

FIG. 5A is an initial irrigation map created following the sequence ofsteps in FIG. 5; and

FIG. 5B is a functional diagram depicting generating an irrigationschedule based on the initial irrigation map of FIG. 5A.

The drawings are not necessarily to scale. The drawings are merelyschematic representations, not intended to portray specific parametersof the invention. The drawings are intended to depict only typicalembodiments of the invention. In the drawings, like numbering representslike elements.

DETAILED DESCRIPTION

Detailed embodiments of the claimed structures and methods are disclosedherein; however, it may be understood that the disclosed embodiments aremerely illustrative of the claimed structures and methods that may beembodied in various forms. This invention may, however, be embodied inmany different forms and should not be construed as limited to theexemplary embodiments set forth herein. Rather, these exemplaryembodiments are provided so that this disclosure will be thorough andcomplete and will fully convey the scope of this invention to thoseskilled in the art.

In the following description, numerous specific details are set forth,such as particular structures, components, materials, dimensions,processing steps, and techniques, in order to provide a thoroughunderstanding of the present invention. However, it will be appreciatedby one of ordinary skill of the art that the invention may be practicedwithout these specific details. In other instances, well-knownstructures or processing steps have not been described in detail inorder to avoid obscuring the invention. It will be understood that whenan element as a layer, region, or substrate is referred to as being “on”or “over” another element, it may be directly on the other element orintervening elements may also be present. In contrast, when an elementis referred to as being “directly on” or “directly over” anotherelement, there are no intervening elements present. It will also beunderstood that when an element is referred to as being “beneath,”“below,” or “under” another element, it may be directly beneath or underthe other element, or intervening elements may be present. In contrast,when an element is referred to as being “directly beneath” or “directlyunder” another element, there are no intervening elements present.

In the interest of not obscuring the presentation of embodiments of thepresent invention, in the following detailed description, someprocessing steps or operations that are known in the art may have beencombined together for presentation and for illustration purposes and insome instances may have not been described in detail. In otherinstances, some processing steps or operations that are known in the artmay not be described at all. It should be understood that the followingdescription is rather focused on the distinctive features or elements ofvarious embodiments of the present invention.

Variation in soil water-holding capacity may cause uniform irrigationsystems to over water particular regions of a field or an irrigationarea in which the soil may exhibit lower water absorption rates due to alarger clay percentage while leaving under irrigated those regions inwhich the soil may have faster water absorption rates due to a highersand composition. In certain geographic regions, such as deserts or aridareas, efficient use of water and fertilizers may be beneficial since aninappropriate response to sub-optimal irrigation may lead to crop lossdue to the harsh environment conditions.

New technologies such as GPS, satellites, aerial remote sensing, andwireless sensors may help assess natural variations in the field moreaccurately so that water and/or fertilizer irrigation may beautomatically adjusted and targeted based on the field conditions. Thismay optimize irrigation efficiency in order to avoid under or overirrigated regions of an irrigation field and in turn improve crop yieldand reduce economic losses. Precision agriculture may include a variablerate or a targeted irrigation system which aim to maintain a constantmoisture or fertilizer level in the soil by automatically adjusting theamount of water or fertilizer delivered based on a real time feedbackfrom in-field or remote sensors and spatial temporal analytics of theirrigation needs (including weather data and forecast) together withlocal Geographic Information System (GIS) data.

Since the irrigation area covered by a particular irrigation system maybe smaller than what may be observed from a satellite image system, GISdata alone is not sufficient to accurately determine the irrigationneeds of the irrigation area. Thus, finer resolution data may be helpfulto better assess the irrigation needs. The finer resolution data may beobtained by utilizing localized sensors and integrating a real timefeedback system where sensor data may drive the irrigation. For example,the sensor data may be processed to provide direct control and automaticscheduling of the irrigation system, thus providing precise and targetedirrigation adapted to the crop needs. Creating real time irrigation mapsand verifying that the right amount of water and fertilizer have beendelivered may present a challenge to current farming practices mainlydue to the additional constrain that the system may need to operate in away such that constant soil moisture may be maintained or fertilizer runoff may be minimized.

Therefore, by implementing an automatic irrigation control andscheduling system, using multiple data sources, embodiments of thepresent disclosure may, among other potential benefits, provide tailoredwater and fertilizer irrigation according to the needs of the irrigationarea in order to reduce over or under irrigation and optimize water andfertilizer delivery.

The present invention generally relates to central pivot irrigationsystems and more particularly to implementing targeted irrigation usingthe central pivot irrigation system with a wireless sensor network. Oneway to implement targeted irrigation using the central pivot irrigationsystem with a wireless sensor network may include obtaining or receivingdata from a variety of sources including local wireless and opticalsensors in order to determine vegetation index, soil moisture, andcanopy leaf temperature, and automatically adjusting the irrigationdelivery based on a real time estimation of these parameters. Oneembodiment by which to implement targeted irrigation using the centralpivot irrigation system with a wireless sensor network is described indetail below by referring to the accompanying drawings in FIGS. 1-5.

Referring now to FIG. 1, a typical configuration for a central pivotirrigation system 100 (hereinafter “central pivot system”) is depicted,according to an embodiment of the present disclosure. The central pivotsystem 100 may be deployed over a relatively large area such as a farmor field that may require a predefined amount of water or fertilizer tobe delivered to a crop.

The central pivot system 100 may generally include a central tower orpivot point 12 located at the center of an irrigation area 14. Thecentral tower 12 may include a pivot mechanism and a main control panel(not shown) generally anchored to a base connected to a fixed watersupply source (not shown). A rotating arm 16 may be rotatably attachedat one end to the central tower 12, and may rotate freely around thecentral tower 12. The rotating arm 16 may be held at an elevatedposition above the ground by a plurality of wheeled framed towers 18(hereinafter “framed towers”). The rotating arm 16 may include aplurality of segments joined together extending outwardly from thecentral tower 12. Each segment, as illustrated in the section view,section A, may include a section of pipe and one of the framed towers18. Each segment may include one or more nozzles 28 positioned atpredetermined points along the section of pipe. The nozzles 28 may beused for dispensing a fluid such as water and/or fertilizer, in agenerally circular spray pattern simultaneously as the rotating arm 16pivots around the central tower 12. Water or fertilizer may be providedto each nozzle 28 via the pipe sections joined together from segment tosegment. Further, each individual nozzle 28 may be fitted with a valve30 which may control how much water is dispensed through each individualnozzle 28. An automatic alignment system may keep the rotating arm 16relatively straight during irrigation and rotation around the centraltower 12.

In an embodiment of the present disclosure, the central pivot system 100may typically rotate at a constant speed of approximately 1 rotation perday to approximately 3 rotations per day around the central tower 12covering the irrigation area 14 in a circular pattern as depicted inFIG. 1. Alternatively, in an embodiment, the rotation speed of therotating arm 16 may be variable, including start and stop motion, withinthe typical limits of the mechanical controls. The rotating arm 16 mayinclude any number of segments from one to as many as 100. The number ofsegments may be set by the granularity of the detection ofirrigation/fertilization needs. The length of the rotating arm 16 may beadjusted according to the system design by adding or removing segments.Each segment of the rotating arm 16 may have a length ranging fromapproximately 1 ft. to approximately 100 ft. The framed towers 18 maykeep the rotating arm 16 at a minimum height of approximately 2 ft. toapproximately 8 ft. above the ground and may be located at a distance ofapproximately 50 ft. to approximately 1000 ft. from one another tomaintain an even distribution of weight and loads between each of theframed towers 18. Each segment of the rotating arm 16 may include anynumber of nozzles 28 where multiple nozzles 28 may be spaced apart fromeach other based on their effective spray coverage. The nozzles 28 maypreferably be spaced close enough such that their effective spraypatterns overlap. It should be noted that the above parameters may beoptimized to achieve any desired irrigation result.

Referring now to FIG. 2, a plurality of optical sensors 20 (hereinafter“optical sensors”) may be installed along the rotating arm 16, accordingto an embodiment of the present disclosure. The optical sensors 20 mayestimate crop and soil properties such as, for example, canopyreflectance, nitrogen distribution, soil temperature, and canopytemperature. The optical sensors 20 may include a down facing batterypowered camera system including a wireless mote 22, a fisheye lens 24and an integrated set of automatically adjustable filters 26 located infront of the fisheye lens 24 as depicted in section B.

The optical sensors 20 move with the rotating arm 16 while photographingand sensing the vegetation underneath. In an exemplary embodiment, theautomatically adjustable set of filters 26 of the optical sensors 20 mayconsist of two or more narrow band filters that may rapidly move infront of the fisheye lens 24. The automatically adjustable set offilters 26 may allow light of a specific bandwidth to pass through thefisheye lens 24 to obtain a spectrally distributed image of the canopyor crop. For example, a green filter may be used to measure canopyreflectance, a red filter may be used to measure nitrogen distribution,and an infrared filter may be used to measure soil and canopytemperatures. Sequential imaging of the same area under differentwavelength may provide information about water needs (normalizeddifferential vegetation index from red and infrared bandwidths) andfertilizer needs (organic components in the soil from green and infraredbandwidths). The images from the optical sensors 20 may be processedlocally on a microprocessor and the irrigation needs may be transmittedvia the wireless mote 22 back to a central computer 31 located at thebase of the central tower 12.

Alternatively, the raw image data from the optical sensor 20 may bewirelessly transmitted to and then processed by the central computer 31to determine the irrigation needs. Each image may be time stamped andgeoreferenced using, for example, a global positioning system (GPS),such that each feature of the acquired images may have associatedcoordinates, for example, longitude and latitude. All images received bythe central computer 31 may be stitched together in a larger map. Ifmultiple sequences of the images are obtained for the same area, thefirst time reference image may be associated as a ground truth andadjustments may be made based on that image. Subsequent images maycontain changes already induced by the irrigation system, such as changein canopy temperature due to water delivery. Both the location of therotating arm 16 in time and time stamp of the image may be used todetermine if irrigation has been carried out or not.

The optical sensors 20 may allow imaging of substantially large areas ofthe field to determine vegetation and soil properties; however limitedby distance above the ground and angle of the fisheye lens.Alternatively, the optical sensor 20 may further include infraredtemperature sensors to measure the temperature of the crop canopy.Additionally, information from individual plants or crop patches may belocalized in space and time, and a sequence of data may be archived bythe central computer 31 to correlate a position of the rotating arm 16with the detected soil moisture and canopy temperature data.

In some embodiments, in addition to the optical sensors 20, a pluralityof microwave devices 34 may be installed along the rotating arm 16 tomeasure complementary soil moisture data. The microwave devices 34 mayinclude a microwave polarimetry generator (VV, HH, VH, and HV) coupledto a sensor that may function at different frequencies and polarizationlevels. The microwave devices 34 may detect wet/dry soil response. Insuch embodiments, frequency modulation may allow a variable depth ofpenetration of the soil. The system may perform real time assessment ofthe reflection of a large area of the field to determine water contentand the spatial distribution of soil moisture. In all cases the opticalsensors 20 and the microwave devices 34 may preferably be positioned infront of each segment such that soil data may be collected immediatelyprior to irrigating a particular area. For example, the optical sensors20 may be mounted to an arm extending outwardly from each segment in thedirection of rotation of the rotating arm 16. Each segment of therotating arm 16 may include one or more optical sensors 20 and one ormore microwave devices 34 to generate the desired characteristic data.

In an alternatively embodiment, either the in-ground 32, the microwavedevices 34, or both may be hard wired to the central computer 31allowing them to communicate via a communication cable rather than awireless signal. This may be desired in situations when the distancebetween the in-ground 32, microwave devices 34 and the central computer31 may be substantially large and there may be a chance to lose thewireless signal.

Referring now to FIG. 3, a plurality of in-ground sensors 32 may bepositioned across the irrigation area 14 to provide a variety of datarelated to the physical characteristics of the soil. In one embodiment,the in-ground sensors 32 may detect, for example, soil moisture and soiltemperature. In another embodiment, the in-ground sensors 32 may includefunctionalized electrodes to measure ionic potential variations causedby fertilizers in the soil. The in-ground sensors 32 may be buriedunderground or may be positioned above ground in a way such that they donot interfere with the central pivot system 100. The in-ground sensors32 may continuously monitor the physical characteristics of the soil.The in-ground sensors 32 may be connected to various microcontrollersand radio devices that may transmit data to a plurality of gatewaydevices 36 (hereinafter “gateway devices”) described below.

It should be noted that each of the above sensors (the optical sensors20, the microwave devices 34, and the in-ground sensors 32) may furtherinclude a GPS receiver from which the precise location of each sensormay be determined. As such, sensor data subsequently received by thecentral computer 31 will include location data of the correspondingsensor, and as such, location data corresponding to the physicalcharacteristics of the irrigation area 14.

The central pivot system 100 may further include one or more gatewaydevices 36 that communicate with any or all of the wireless sensors, forexample the in-ground sensors 32, the optical sensors 20, or themicrowave devices 34, of the central pivot system 100. Morespecifically, the gateway devices 36 may be mounted on the framed towers18 as depicted in FIG. 3. The gateway devices 36 may collect or receivedata wireles sly from any or all of the wireless sensors, andsubsequently transmit that data to the central computer for furtheranalysis. Communication between the gateway devices 36 and the wirelesssensors may be conducted on any known wireless protocol, such as, forexample, any of the wireless protocols described below.

In one embodiment, the wireless sensors may be programmed to transmitdata at fixed time intervals. In another embodiment, the wirelesssensors, and more specifically the in-ground sensors 32, may besynchronized to transmit information only when the gateway devices 36are in close proximity, due to the fact that the gateway devices 36 movewith the rotating arm 16 relative to the in-ground sensors 32 which havefixed locations in the ground. The gateway devices 36 may process, inreal time, the acquired data from the in-ground sensors 32 and transmitit to the central computer 31 to adjust the irrigation schedule, speedof the rotating arm 16 or request additional information from othersensors.

Referring now to FIG. 4, a functional block diagram of a hybrid wiredand wireless computing environment 200 is shown, according to anembodiment of the present disclosure. The computing environment 200includes the central computer 31, the microwave devices 34, the valves30, the optical sensors 20, the gateways devices 36, and the in-groundsensors 32, all interconnected over a network 40.

In a preferred embodiment of the present invention, the central computer31, the microwave devices 34, the valves 30, the optical sensors 20, andthe gateway devices 36 are all Ethernet and wireless enabled; howeverthe in-ground sensors 32 are only wireless enabled. In particular, thewireless enabled components of the network 40 all support the followingprotocols: the IEEE Std 802.3-2008 Part 3: Carrier Sense Multiple Accesswith Collision Detection (CSMA/CD) Access Method and Physical LayerSpecifications (“Ethernet”); the IEEE Std 802-11n-2009 Part 11: WirelessLAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications;and the IEEE Std 802.15.4a-2007 Part 15.4: Wireless Medium AccessControl (MAC) and Physical Layer (PHY) Specifications for Low-rateWireless Personal Area Networks(WPANs) (“802.15”). IEEE and 802 areregistered trademarks of the Institute of Electrical and ElectronicsEngineers, Incorporated.

The IEEE Std 802.11n-2009 wireless protocol, commonly referred to as802.11n, is a later version of the IEEE Std 802.11-1999 wirelessprotocol. Computing devices using the 802.11n wireless protocoltypically have a wireless range of as much as 70 meters, although actualranges in a working environment can be substantially less. Otherversions of the 802.11-1999 standard, such as the commonly used802.11b-1999 and 802.11g-2003 wireless protocols, have a range of abouthalf that of the 802.11n wireless protocol. Although in the preferredembodiment, computing devices may support the 802.11n wireless protocol,those skilled in the art will recognize that embodiments of theinvention can be practiced using the IEEE Std 802.11-1999 wirelessprotocol, and any later versions of this protocol including 802.11b, and802.11g. The 802.11n wireless protocol, and other versions of the IEEEStd 802.11-1999 wireless protocol, are collectively referred to hereinas the 802.11 wireless protocol.

The IEEE Std 802.15.4a-2007 is a later version of the Bluetooth-basedIEEE Std 802.15.1-2002 wireless protocol. Computing devices using the802.15.4a wireless protocol typically have a wireless range of about 10meters, although certain implementations, such as the ultra-wide bandphysical layer (UWB PHY) have a precision ranging capability of aboutone meter. Although in the preferred embodiment, computing devices 110support the 802.15.4a wireless protocol, those skilled in the art willrecognize that embodiments of the invention can be practiced using theIEEE Std 802.15.1-2002 wireless protocol, and any later versions of thisprotocol. The 802.15.4a wireless protocol, and other versions of theIEEE Std IEEE Std 802.15.1-2002 wireless protocol, are collectivelyreferred to herein as the 802.15 wireless protocol.

In a preferred embodiment, network 40 represents a hybrid wired/wirelessnetwork that includes a wired Ethernet network, and a wireless protocolnetwork operating in infrastructure mode. The network 40 may includeboth Ethernet and 802.11 wireless protocol routers (not shown) havingfixed physical locations. With regards to the Ethernet routers, eachport that is used to connect to a wireless enabled device, such asin-ground sensors 32, can be associated with a physical location. Forexample, although an Ethernet router may be located an equipment closet,a port on the router may be connected through system wiring to aspecific device on the network. The router port may be associated to thenetwork component by, for example, a database of such associations.Thus, from a network perspective, a network component that is identifiedas being connected to the router port can be mapped to a physicallocation by performing a router port to physical location lookup in thedatabase. In the present example, a physical location of a particularnetwork component may include a segment number indicating which segmentof the rotating arm 16 the particular network component is located. Ifmultiple network components are located in a single segment, thephysical location may include a network component number in addition toa segment number.

The 802.11 wireless protocol routers are located in fixed physicallocations. For example, wireless routers might be placed in acentralized location, for example the central tower 12, to provideoptimal coverage for wireless enabled network components in the system.

In the preferred embodiment, the central computer supports theinfrastructure and ad hoc modes of the 802.11 wireless protocol. Themost common manner to use an 802.11 wireless protocol network is in“infrastructure” mode. In this mode, wireless network componentscommunicate with a wireless access point, for example, an 802.11wireless protocol router. Typically, the wireless router serves as abridge to a wired local area network (LAN) or wide area network (WAN).In such a network, wireless devices do not communicate directly witheach other, but rather via the wireless access point and usually over aLAN or WAN. All wireless devices that are connected to a network via aspecific wireless access point are configured to use the same serviceset identifier (SSID), which serves as an identifier for all devicesconnected to a specific wireless access point. In 802.11 wirelessprotocol infrastructure mode, the SSID for a wireless access pointtypically is the access point's media access control (MAC) address. AMAC address is a unique 48-bit number assigned to the network interfacecard (NIC) of each wireless device by its manufacturer.

In 802.11 wireless protocol ad hoc mode, a temporary wireless network isestablished between computers and devices. In an ad hoc wirelessnetwork, computers and network components connect directly to each otherrather than to a wireless access point. To set up an ad hoc wirelessnetwork, each wireless adapter must be configured for ad hoc mode ratherthan infrastructure mode. In addition, all wireless adapters in the adhoc wireless network must use the same SSID and the same channel number.Each wireless network component can only be a transmitter (TX) or areceiver (RX) at any given time. Communication among wireless networkcomponents is limited to a certain transmission range or distance, andwireless network components in the ad hoc wireless network share thesame frequency domain to communicate. Within such a range, only onetransmission channel is used, covering the entire bandwidth.

In the preferred embodiment, the central computer also support the802.15 wireless protocol. Similar to the 802.11 wireless protocol in adhoc mode, 802.15 wireless protocol can establish wireless connectionsdirectly between enabled network components. An 802.15 wireless protocolnetwork established between two or more enabled network components isreferred to as a wireless personal area network (WPAN). The 802.15wireless protocol is a packet-based protocol with a master-slavestructure. One master may communicate with up to seven slaves in a“piconet” network, and the slaves in the piconet can only communicatewith the master. An 802.15 wireless protocol network is typicallyestablished when one 802.15 wireless protocol enabled network componentin discoverable mode (the slave device) responds to an inquiry fromanother enabled network component seeking other devices (the masterdevice) to connect to. The network component in discoverable moderesponds to the inquiry with identifying information that can includeits MAC address.

In general, the network 40 and the wireless network components connectedto it can support any combination of communication protocols where atleast one of the protocols, is a wireless protocol that supports eitherdirect peer-to-peer communications or a larger wireless range than theother. In addition, one or more of the central computer in the network40 may be associated with a fixed physical location.

With continued reference to FIG. 4, the optical sensors 20, themicrowave devices 34, and the in-ground sensors 32 may together make upa sensor network. Data from each sensor in the sensor network may beintegrated in real time analytics with additional external data sets(weather, solar radiation, crop models etc.) on the central computer 31.The input from the sensor network may be integrated into decision modelsto determine optimum time or decide if irrigation may be delayed. Theirrigation needs may then be determined based on the analysis andindividual valves 30 corresponding with individual nozzles 28 may beopened to allow irrigation to begin at designated locations along therotating arm 16 corresponding with target area(s) of the irrigation area14 where the system has indicated a water deficiency. Stateddifferently, after data is collected and processed, the central computermay issue commands to the valves 30 to adjust water flow of individualnozzles 28 according to targeted irrigation needs. Alternatively, thenozzles 28 may operate in a pulsed mode which may be beneficial in caseswhere a reduced amount of water may need to be delivered. In the pulsedmode, the amount of water required may be distributed within the timethe rotating arm 16 pivots around the central tower 12 such that thewater may get into the soil rather than running off. In someembodiments, it may be beneficial to determine the ability of the soilto absorb the water at certain rates. The irrigation needs mentionedabove may be determined by combining data collected and processed fromthe microwave devices 34, the optical sensors 20 and the in-groundsensors 32.

Referring now to FIG. 5, a flow chart 150 depicting a sequence of stepsto implement targeted irrigation using the central pivot irrigationsystem 100 with a wireless sensor network, is shown, according to anembodiment of the present disclosure. An initial step 202 may indicatethe start of the central pivot system 100 (FIG. 3) rotation around theirrigation area 14 (FIG. 3). Next, data may be collected from a varietyof sources. At this step, the strength of the signal may be checked andthe ID of all sensors within the target area combined with data andtimestamp of data acquisition may be retrieved. In-field data may beacquired in step 204 from optical sensors 20 (FIG. 3) and in-groundsensors 32 (FIG. 3) to determine, for example, moisture level in thesoil. In embodiments in which microwave devices 34 have been installed,soil data from these devices may also be obtained at this point of thedata acquisition process. The areas of the field that may require morewater or larger amounts of fertilizer (also referred to as spatialvariability) may be detected in step 206 from remote satellite data,spatial changes in soil water holding capacity may also be identifiedwhile current soil variation maps may be delineated in step 208. Datafrom external sources (weather data, satellite data, solar radiationdata, and crop models) may be acquired by the central computer 31 andsend back to individual computational nodes to estimate irrigationneeds. The estimated information is retransmitted to the centralcomputer 31.

An initial spatial irrigation map (FIG. 5A) of the field with delineatedirrigation zones (1, 2, 3, 4 and 5) may be created in step 210 afterintegrating the data obtained from steps 204, 206, and 208 in thecentral computer 31 located in the central tower 12 (FIG. 3). Theinitial spatial irrigation map (FIG. 5A) may provide real time detailsabout current soil moisture and crop conditions from which an irrigationschedule may be established in the central pivot system 100 (FIG. 3) asdescribed in FIG. 5B. If the initial estimation of soil moisture (orfertilizer) level is above a predetermined threshold, then the wateremitter devices located in the rotating arm 16 (FIG. 3) may not beactivated and irrigation is not performed (step 214). Conversely, if theestimated soil moisture (or fertilizer) level is below the predeterminedthreshold, electro transpiration may be calculated in step 218 based onin-field sensors data, weather data (step 216), and satellite data. Anirrigation schedule is then generated in the central computer 31including the amount of water required for irrigation, then a commandmay be sent to one or more segments of the rotating arm 16 (FIG. 3)containing the nozzles 28 in order to deliver water or fertilizer toareas in which deficiencies were detected (step 220). Once irrigationhas been completed (step 222) the rotating arm 16 (FIG. 3) may be movedto a new position (step 224) and the process starts again. If receivedinformation detects that the weather may change and a rain event may belikely to occur, the central computer 31 may integrate the weatherinformation in real time and adjust the irrigation schedule accordingly.If the rainfall was below the predicted level, the difference may beadded to the next day irrigation schedule. In case of a larger amount ofrain fall, the next day irrigation may be delayed until data from theinfield sensors indicates that the soil moisture level may be below athreshold or plants are stressed.

It should be noted that the spatial irrigation maps generated based ondata from the in-ground sensors 32 and the optical sensors 20 mayprovide dynamic real time representations of crop conditions. Then,customized and targeted irrigation may be provided base on real timemodeling of soil properties. These dynamic real time representations ofcrop conditions, may also allow automatically adjusting the functioningof the nozzles 28 according to current water or fertilizer needs.Additionally, in some embodiments, the movement of the rotating arm 16may be correlated with the data obtained from the in-ground and opticalsensors 32, 20 in order to reduce water waste and minimize waterrun-off. If the amount of water to be delivered to an area is largerthan expected, the rotation speed of the rotating arm 16 may be changedto deliver the water under the flow constrain. The velocity of therotating arm 16 may be directly related to the water needs. In otherembodiments, the movement of the rotating arm 16 may be relativelyconstant, and the targeted irrigation may be carried out by turningindividual nozzles 28 on and off as needed based on the irrigation mapgenerated by the central computer 31.

Therefore, by forming a wireless sensor network across an irrigationarea maintained by a central pivot irrigation system, real timeinformation about soil and vegetation conditions may be acquired andcombined with data originated from remote observation of the field inorder to precisely determine the required amount of water or fertilizer.

The amount of water or fertilizer required in each irrigation zonewithin the central pivot system 100 may be assessed through in-fieldsensing or remote optical monitoring of the crop by detecting thevegetation and leaf area index of each irrigation zone. Through realtime analytics, irrigation maps may be created showing zones within thecentral pivot system that may require to be irrigated. Once the spatialextent and amount of water required for irrigation is determined,commands may be issued to segments of the irrigation arms such that adifferential irrigation pattern is set for the central pivot system 100.In an embodiment, each irrigation segment may be independentlycontrolled, such that one segment is irrigating while another segment isnot irrigating. The length of the segments may be adjusted according tothe local conditions and the spatial variability of the soil, thusimproving water and fertilizer delivery, compared to uniform irrigationsystems. In other embodiments, as discussed above, more precision may beobtained by controlling the flow of individual nozzles. The embodimentspresented above efficiently maintain constant soil moisture at thedesired depths, and allow for confirmation that any desired irrigationlevels have been achieve using the same real time monitoring system. Forexample, the central computer 31 may process the information from thein-ground sensors 32 about excessive watering, verify this informationwith other sensors in the sensor network to make the decision ofshutting down the valves that may be delivering excessive amounts ofwater.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiment, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdisclosed herein.

What is claimed is:
 1. A system comprising: a plurality of opticalsensors located along at least one pipe segment of a rotating arm thatpivots around an irrigation area of a field, wherein the plurality ofoptical sensors continuously monitors soil and vegetation conditions andtransmits sensed data to a central computer; and a plurality ofin-ground sensors scattered in the irrigation area of the field, whereinthe plurality of in-ground sensors continuously monitors soil conditionsand transmits sensed data to a plurality of gateway devices located inthe rotating arm, wherein the plurality of gateway devices transmitsdata from the plurality of in-ground sensors to the central computer,wherein the central computer integrates data from the plurality ofoptical sensors and the plurality of in-ground sensors with externaldata acquired by the central computer to determine water and fertilizerneeds based on which an irrigation schedule is created.
 2. The system ofclaim 1, wherein the plurality of optical sensors comprises: a downfacing battery powered camera system comprising a wireless mote, afisheye lens, and an integrated set of automatically adjustable filters,the automatically adjustable set of filters allows light on a specificbandwidth to pass through the fisheye lens to obtain spectrallydistributed images of the canopy or crop, wherein a location and time ofeach image obtained by the optical sensors is provided by a globalpositioning system (GPS).
 3. The system of claim 1, wherein the soil andvegetation properties detected by the plurality of optical sensorscomprises: canopy reflectance, vegetation index, nitrogen distribution,soil temperature and canopy temperature.
 4. The system of claim 1,wherein the soil and vegetation properties detected by the plurality ofoptical sensors are transmitted via the wireless mote to the centralcomputer, the central computer correlates detected soil and vegetationproperties with a position of the rotating arm.
 5. The system of claim1, wherein the soil properties detected by the plurality of in-groundsensors comprises: soil moisture, soil temperature, nitrogenconcentration and ionic potential variations caused by fertilizers inthe soil.
 6. The system of claim 1, wherein the plurality of in-groundsensors are connected to various microcontrollers and radio devices totransmit acquired data to the plurality of gateway devices, theplurality of gateway devices process data from the in-ground sensors inreal time and transmit processed data to the central computer to adjustthe irrigation schedule, a speed of the rotating arm or requestadditional information from additional sensors.
 7. The system of claim1, further comprising: a plurality of microwave devices located alongone or more of the pipe segments of the rotating arm, the microwavedevices detecting soil moisture information to complement propertiesdetected by the plurality of in-ground sensors scattered in theirrigation area of the field.
 8. The system of claim 7, wherein theplurality of microwave devices comprises: a microwave polarimetrygenerator (VV, HH, VH, and HV) coupled to a sensor that functions atdifferent frequencies and polarization levels.
 9. A system comprising: aplurality of pipe segments joined together end-to-end and supportedabove the ground on wheeled framed towers, the plurality of pipesegments are rotatably attached at one end to a central tower such thatthey rotate freely about the central tower, each pipe segment comprisingone or more nozzles for dispensing a fluid on an irrigation area belowthe pipe segments; a plurality of optical sensors located along one ormore of the pipe segments, wherein the optical sensors estimate soil andvegetation properties and generates optical sensor data; a plurality ofin-ground sensors at least partially embedded into the soil within theirrigation area, wherein the in-ground sensors detect soil propertiesand generates in-ground sensor data; a gateway device attached to one ormore of the wheeled framed towers, wherein the plurality of in-groundsensors wirelessly transmit the soil properties to the gateway device;and a central computer located in the central tower, wherein the gatewaydevice wireles sly transmits the in-ground sensor data to the centralcomputer, and wherein the central computer determines the irrigationneeds of the irrigation area in the form of an irrigation map byprocessing the in-ground sensor data, the optical sensor data, andexternal data, wherein the central computer communicates with individualflow control valves corresponding with each nozzle to open or close toirrigate one or more zones identified by the irrigation map.
 10. Thesystem of claim 9, wherein the plurality of optical sensors comprises: adown facing battery powered camera system comprising a wireless mote, afisheye lens, and an integrated set of automatically adjustable filters,the automatically adjustable set of filters allows light on a specificbandwidth to pass through the fisheye lens to obtain spectrallydistributed images of the canopy or crop, wherein a location and time ofeach image obtained by the optical sensors is provided by a globalpositioning system (GPS).
 11. The system of claim 9, wherein the opticalsensor data includes canopy reflectance, vegetation index, nitrogendistribution, soil temperature and canopy temperature.
 12. The system ofclaim 9, wherein the soil and vegetation properties detected by theplurality of optical sensors are transmitted via the wireless mote tothe central computer, the central computer correlates detected soil andvegetation properties with a position of the rotating arm.
 13. Thesystem of claim 9, wherein the soil properties detected by the pluralityof in-ground sensors comprises: soil moisture, soil temperature,nitrogen concentration and ionic potential variations caused byfertilizers in the soil.
 14. The system of claim 9, wherein thein-ground sensors are connected to various microcontrollers and radiodevices to transmit acquired data to the gateway device, the gatewaydevice processes data from the in-ground sensors in real time andtransmit processed data to the central computer to adjust the irrigationschedule, a speed of the rotating arm or request additional informationfrom additional sensors.
 15. The system of claim 9, wherein the externaldata comprises: weather data, satellite data, solar radiation data, andcrop models acquired by the central computer.
 16. The system of claim 9,further comprising: a plurality of microwave devices located along oneor more of the pipe segments of the rotating arm, the microwave devicesdetecting soil moisture information to complement properties detected bythe plurality of in-ground sensors scattered in the irrigation area ofthe field.
 17. The system of claim 16, wherein the plurality ofmicrowave devices comprises: a microwave polarimetry generator (VV, HH,VH, and HV) coupled to a sensor that functions at different frequenciesand polarization levels.
 18. A method comprising: providing a centralpivot irrigation system comprising a plurality of pipe segments joinedtogether end-to-end and supported above the ground on wheeled framedtowers, wherein the plurality of pipe segments are rotatably attached atone end to a central tower such that they rotate freely about thecentral tower, wherein each pipe segment comprises one or more nozzlesfor dispensing a fluid on an irrigation area below the pipe segments;acquiring in-field data from a wireless sensor network comprising aplurality of optical sensors located along one or more of the pipesegments, the optical sensors estimating soil and vegetation propertiesand generating optical sensor data, a plurality of in-ground sensors atleast partially embedded into the soil within the irrigation area, thein-ground sensors detecting soil properties and generating in-groundsensor data, and a gateway device attached to one or more of the wheeledframed towers, wherein the plurality of in-ground sensors wirelesslytransmits the soil properties to the gateway device and the gatewaydevice wirelessly transmits the in-ground sensor data to a centralcomputer located in the central tower; and determining in the centralcomputer irrigation needs of the irrigation area in the form of anirrigation map by processing the in-ground sensor data, the opticalsensor data, and external data, wherein the central computercommunicates with individual flow control valves corresponding with eachnozzle to open or close to irrigate one or more zones identified by theirrigation map.
 19. The method of claim 18, wherein acquiring in-fielddata from the wireless sensor network further comprises: obtaining datafrom a plurality of microwave devices located along one or more of thepipe segments of the rotating arm, the microwave devices detecting soilmoisture information to complement properties detected by the pluralityof in-ground sensors scattered in the irrigation area of the field. 20.A computer readable non-transitory article of manufacture tangiblyembodying computer readable instructions which, when executed, cause acomputer to carry out the steps of a method according to claim 19, themethod comprising: providing a central pivot irrigation systemcomprising a plurality of pipe segments joined together end-to-end andsupported above the ground on wheeled framed towers, wherein theplurality of pipe segments are rotatably attached at one end to acentral tower such that they rotate freely about the central tower,wherein each pipe segment comprises one or more nozzles for dispensing afluid on an irrigation area below the pipe segments; acquiring in-fielddata from a wireless sensor network comprising a plurality of opticalsensors located along one or more of the pipe segments, the opticalsensors estimating soil and vegetation properties and generating opticalsensor data, a plurality of in-ground sensors at least partiallyembedded into the soil within the irrigation area, the in-ground sensorsdetecting soil properties and generating in-ground sensor data, and agateway device attached to one or more of the wheeled framed towers,wherein the plurality of in-ground sensors wirelessly transmits the soilproperties to the gateway device and the gateway device wirelesslytransmits the in-ground sensor data to a central computer located in thecentral tower; and determining in the central computer irrigation needsof the irrigation area in the form of an irrigation map by processingthe in-ground sensor data, the optical sensor data, and external data,wherein the central computer communicates with individual flow controlvalves corresponding with each nozzle to open or close to irrigate oneor more zones identified by the irrigation map.